Andy (and Brian?) I don't know if that can easily be improved... Here is what I typically get when I introduce a problem in wmgr: Traceback (most recent call last): File "/home/becla/stack/Linux64/flask/0.10.1+11/lib/python/Flask-0.10.1-py2.7.egg/flask/app.py", line 1817, in wsgi_app response = self.full_dispatch_request() File "/home/becla/stack/Linux64/flask/0.10.1+11/lib/python/Flask-0.10.1-py2.7.egg/flask/app.py", line 1477, in full_dispatch_request rv = self.handle_user_exception(e) File "/home/becla/stack/Linux64/flask/0.10.1+11/lib/python/Flask-0.10.1-py2.7.egg/flask/app.py", line 1378, in handle_user_exception if isinstance(e, typecheck): TypeError: isinstance() arg 2 must be a class, type, or tuple of classes and types 2015-09-09 11:37:43,574 [PID:4849] [INFO] (_log() at _internal.py:87) werkzeug: 127.0.0.1 - - [09/Sep/2015 11:37:43] "POST /dbs HTTP/1.1" 500 - to get a sensible stack trace that is actually useful, I end up commenting out: [log in to unmask](DbException) [log in to unmask](sqlalchemyExc) [log in to unmask](MySQLdb.Error) [log in to unmask](MySQLdb.Warning) #def dbExceptionHandler(error): # """ All leaked database-related exceptions generate 500 error """ # return errorResponse(500, error.__class__.__name__, str(error)) This is the error I would get if errorhandler code would be commented out: Traceback (most recent call last): File "/home/becla/stack/Linux64/flask/0.10.1+11/lib/python/Flask-0.10.1-py2.7.egg/flask/app.py", line 1817, in wsgi_app response = self.full_dispatch_request() File "/home/becla/stack/Linux64/flask/0.10.1+11/lib/python/Flask-0.10.1-py2.7.egg/flask/app.py", line 1477, in full_dispatch_request rv = self.handle_user_exception(e) File "/home/becla/stack/Linux64/flask/0.10.1+11/lib/python/Flask-0.10.1-py2.7.egg/flask/app.py", line 1381, in handle_user_exception reraise(exc_type, exc_value, tb) File "/home/becla/stack/Linux64/flask/0.10.1+11/lib/python/Flask-0.10.1-py2.7.egg/flask/app.py", line 1475, in full_dispatch_request rv = self.dispatch_request() File "/home/becla/stack/Linux64/flask/0.10.1+11/lib/python/Flask-0.10.1-py2.7.egg/flask/app.py", line 1461, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) File "/usr/local/home/becla/stack/repos/qserv/lib/python/lsst/qserv/wmgr/dbMgr.py", line 194, in createDb dbConn = Config.instance().privDbEngine().connect() File "/usr/local/home/becla/stack/repos/qserv/lib/python/lsst/qserv/wmgr/config.py", line 120, in privDbEngine inst = engineFactory().getEngineFromArgs(**kwargs) NameError: global name 'engineFactory' is not defined See? That is so much better. I entered engineFactory instead of EngineFactory. There is no way I could have figured it out from the previous stack trace... How can we improve that? Jacek ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the QSERV-L list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=QSERV-L&A=1